Piano-playing device



Get. 19 1926.

H, K. SANDELL PIANO PLAYING DEVICE Original Filed June 14, 1922 2 Sheets-Sheet 1 I @6725? n fidmzdei 1a 3 gfiygi H. K. SANDELL PIANO PLAYING DEVICE Original Filed June 14, 1922 2 Sheets-Sheet 2 I/IIIIII Patented Oct. 19, 1926.

UNITED STATES PATENT QFFICE.

HENRY K. SANDELL, OF CHICAGO, ILLINOIS, ASSIGNOB T0 MILLS NOVELTY COM- PANY, ,OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

PIANO-PLAYING DEVICE.

Original application filed June 14, 1922, Serial No. 568,226. Divided and this application filed April 9, 1924. Serial No. 705,240.

The present invention relates to a piano playing device in combination with an electfoniaget device. Ina piano playing device, the improved electromagnet device may be usefully employed for various purposes. For example, it may be employed for the purpose of controlling the position of a hamliner-rail, or itmay be employed for controlling the position of a damper.

In meansof the character referred to, the improved device can be most advantageously used in an embodiment in which the armature of one electromagnet serves to actuate and releasably' hold an actuating member employed in connection with the piano action, and the armature of another electromagnet serves to interlockingly engage the first-mentioned armature and prevent its return to its initial position until the arm'a ture of the second-mentioned magnet is withdrawn by energizing its coil.

The present application constitutes a division of Sandell application No, 568,226, filed June 14, 1922. The invention is illustrated in one preferred embodiment in the accompanying drawings, in which- Fig. 1 is a broken vertical sectional View of a piano playing device, showing also the improved electromagnet device used in conjunction therewith; Fig. 2, a broken front elevational View of the mechanism shown in Fig. 1; Fig. 3, a broken sectional viewshowingthe construction of the electromagnet device; Fig. 4, a broken plan View of the deviceshown in Fig. 3; and Fig. 5, a diagrammatic view illustrating the manner in which the hammer-rail of the piano action is controlled by the improved electromagnet device.

It may be stated that in a piano action, one method of controlling expression is by limiting the range of movement of the ham mer. This may be accomplished by controlling the position of the hammer-rail which limits the swing of the hammer away from the string, thus regulating the stroke of the hammer.

One useful application of the improved electromagnet device is illustrated in the drawings in which the electronragnet device is employed to control the position of the lianimer rail.

the ccnstruotion illustrated, A;

sents the frame upon which are supported the strings A of the piano; B, a bracket carried by said frame, and upon which is mounted the iano action B which is V equipped with a hammer B? and a hammer rail B 0, a jack-butt of the piano action; I), an electromagnet for actuating the ackbutt; E, an actuating lever adapted to retract thehammer'rail to the position shown in Fig. 1; and F, an electromgnet device comprising a pair of electromagnets having interlocking in-matures, one of whieh is adapted to actuate the lever E. '7

The piano action illustrated is, in its general construction, well known, and need not be described in detail. g

The hammer B is actuated through the medium of the usual mechanism by means of the jack-butt C. The ack-butt C is actuated by a riser 1 which is carried by the movable core 2 of theelectromagnet D. The magnet D may have its coil energized by an alternating current, and when energized will lift the core 2 and actuate the jack-butt C through the medium of the riser 1, thus causing the hammer to strike the string. The hammer-rail B is equipped with arms 3 (one shown) which are mounted on pivots 3 carried by thebracket B.

The lever E has its central portion mounted on a pivot 4: carried by a member of the bracket. A spring 5 tends to draw the hammer-rail towards the strings. The'upper end of the lever E is disposed back o f and engages a felt covered stud 6 which projects from the end of the hammer-rail. The lower end of the lever E bears against the end of the armature, or core, of the actuating electromagnet of the device F.

The device F comprises an actuating mag net F, and'a looking or latching magnet F Magnets F and F are controlled by electric circuits, preferably carrying alternating current, as will be presently described. Themagnet F comprises a coil 7 encircling a tube of non-magnetic material 8; a laminated iron frame 9 forming a magnetic circuit about the coil, one side of the frame comprising, however, a plate 9 carried by an angle 10; and a laminated core 11 which normally occupies a retracted position, but which is adapted to be drawn into the coil i when the latter 1mg vied; The core Iii;

- circuit is equipped with a stem 12 which works through a felt bushing 13 which extends through the end of the frame 9. The member 13 extends inside of the frame and is encircled by a bearing 1 L having a conical seat conforming to the conical end 11 of the core. The stem 12 is equipped at its outer end with a head 12 which is provided with a recess in which is seated a felt disk 15 which engages the lower end of the lever E. Interposed between the head 12 and the end of the frame 9 is a felt washer 16. When the magnet F is energized, the core 11 is drawn into thecoil 7, thus moving the lever E to the position shown in Fig. 1 and thereby retracting the hammer-rail B The. magnet F is disposed at right angles to the magnet F, and its armature is adapted to be projected by means of a spring and caused to interlock with the armature of the magnet F. In this manner, the armature of the magnet F may be held in the projected position shown in Fig. 1 until the magnet F is energized.

The magnet F comprises a coil 17 through which extends a tube of non-magnetic material 18; an iron frame 19 which extends about the coil in a longitudinal direction; a core 20 movable in the tube 13; and a spring 21 adapted to project the core to a position shown in Figs. 1 and 3. The core 20 is equipped, at its ends, with projecting stems 20 and 20 which work through bearings 22 and 23 with which the ends of the tube 18 are fitted. The lower end of the spring 21 bears against the inner end of the bearing 23. The stem 20 is equipped with a head, or pad 24: which is adapted to interlock with the head with which the armature of the magnet F is provided, as shown in Fig. 1.

Fig. 5 illustrates the manner in which the hammer-rail B may be controlled by the magnet device F. In this figure, 25 represents a metallic tracker-bar, or roll, of a selfplaying piano. One main 26 of an electric is connected with the member 25. The other main 27 has a branch 2'7 leading to one end of the magnet F and a branch 27 leading to one end of the magnet F. From the other end of the magnet F a conductor 28 leads to a contact 29 which is adapted to co-act with the tracker-bar 25. From the other end of the magnet F the conductor 30 leads to a contact 31 which is adapted to co-act with the tracker-bar 25. Additional contacts 32 are shown, which co-actwith the bar 25. These contacts have conductors 32 which lead to the electromagnets D which serve to actuate the piano actions in a well known manner. A note sheet,

or music roll, 33 is interposed between the,

contactsmentioned and the tracker-bar 25, it being understood that any one of these contacts may come into contact with the bar 25 when a suitable slot in the note sheet permits such action.

It will be seen that the ccntact 31' controls the action of the magnet F". The note sheet may be provided with a series of expressioncontrolling slots co-acting with the contact 31. hen the contact 31 engages one of these slots, it closes the circuit of the magnet F, thereby causing the core 11 to be drawn into the magnet, and thus actuating the lever E and causing it to retract the hammer-rail B so that the hammer will be permitted a greater amplitude of movement. \Vhen the armature 11 is actuated, the armature 20 is projected by the spring 21, thus causing the armature 1.1 to be locked, or latched, in the projected position. Thus, the hammer-rail will remain. in retracted position until the contact 29 engages one of a series of slots which control the action of the magnet F In the meantime, the circuit through conductor 30 may be broken. is closed through the conductor 28, the magnet F is energized, and thus the armature 20 is withdrawn or retracted. This permits the lever E to be returned to its normal position by the spring 5, the lever E, in turn, forcing the magnet 11 to the partially ejected position which it normally occupies, as shown in Fig. 3.

While the magnet device has been illustrated for use in controlling expression by controlling the position of the hammer-rai the magnet device may be employed for any similar purpose, as for example, to control hen the circuit I the position of the damper 34 shown in Fig.

trated with reference to the control of the hammer-rail. It is unnecessary to illustrate and describe a dupllcate of the magnet device F for use in controlling the action of the damper, as this will be readily understood by those skilled in the art in view of the explanation of the improved device shown in connection with the hammer-rail.

It is preferred to employ an alternating current for operating the electromagnet device F, and the letters A. C. are employed in Fig. 5 to indicate the use of an alternating current.

It will be understood by those skilled in the art that it is possible to readily control the position of the hammer-rail, or other expression device, by means of the improved magnet device; that the hammer-rail may be retracted at the instant desired by means of the magnet F, whose circuit is closed only for a very brief period; and that the release of the hammer-rail may be effected by means of the magnet F at any desired instant by energizing the magnet F The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, but the appended claims should be construed as broadly as permissible, in view of the prior art.

lVhat I regard as new, and desire to secure by Letters Patent, is:

1. In a device for intermittently operating movable parts of piano actions, the combination with a movable member of said action, of an actuating electromagnet equipped with an armature adapted to actuate said member, a circuit for said electromagnet having a contact and a tracker-bar forming a part thereof, a note-sheet control ing the closing and opening of said circuit at said contact, a second electromagnet provided with a spring-equipped armature adapted to interlockingly engage the firstmentioned armature, and a circuit for said second-mentioned electromagnet having a contact co-acting with said tracker-bar and note-sheet, said note-sheet permitting the energizing of the first-mentioned electromagnet to cause its armature to be actuated and said note-sheet serving afterwards to permit the energizing of the second-mentioned electromagnet to cause its armature a coil disposed in front of the first-mentioned coil with its axis perpendicular to said stem, a core movable through said second-mentioned coil and having a stem equipped with a head adapted to interlock with said first-mentioned head, a sprin tending to project said second-mentione core into interlocking position, circuits for said lectromagnets having contacts and a tracker-bar forming a part of such circuits, and a note-sheet controlling the closing and opening of said circuits at said contacts, said actuating magnet operating upon closure of its circuit to actuate the movable member of the piano action whereupon the core of the latch magnet serving to interlockingly engage the core of the actuating magnet, and said note-sheet serving to energize the latch magnet and withdraw its core from the interlocking position after the circuit of the actuating magnet has been interrupted by the note-sheet,

HENRY K. SANDELL. 

